Our ultimate goal is to contribute in a meaningful way to the cure of diabetes through islet transplantation. We posit that early loss of transplant islet mass at the implantation site significantly reduces the functional potential of the freshly purified islet preparation. Certain anatomic and immunologic variables impact on the early fate of the implanted cells. The overall goal of the proposal is to define how the transplant location, the make-up of the transplanted cells (free cells, cellular matrix structures, or islets), and the immune responsiveness of the host affect cellular viability and function. We hypothesize that: 1) early loss of viable islet mass significantly reduces the functional potential of the freshly purified islet preparation; 2) that rates of loss of cell viability depend on engraftment site, the vigor of immediate host non-specific inflammatory responses, and the composition of the cellular structures transplanted. The specific aims are: 1. To develop a useful method of real-time bioluminescent imaging as a modality to monitor the fate of transplanted "tagged" islets from transgenic rat insulin II promoter (RIP)-luciferase donor strain mice. 2. To create effective adeno and adeno-associated viral vectors containing the RIP with two reporter genes: luciferase and green fluorescent protein for transfection of purified mouse and human islets. 3.To apply bioluminescent imaging techniques to monitor the fate of transplanted MIN6 -cell lines expressing luciferase using a scaffold matrix. The aims will be accomplished by applying the general methods of real-time, non-invasive bioluminescent imaging to the specific field of islet transplantation. This imaging modality will permit visualization of "tagged' transplanted islets or -cells in the living mouse. Through serial post-transplant monitoring, it will be possible to define how the fate of the viable islet mass is affected by anatomic and immunologic considerations that directly relate to transplant functional outcome.